WO2022215381A1

WO2022215381A1 - Connecting structure, and antenna module

Info

Publication number: WO2022215381A1
Application number: PCT/JP2022/007848
Authority: WO
Inventors: 夏海南谷; 健吾尾仲
Original assignee: 株式会社村田製作所
Priority date: 2021-04-09
Filing date: 2022-02-25
Publication date: 2022-10-13
Also published as: US20240039143A1

Abstract

This connecting structure is for connecting an antenna board (120) and a rigid board (300), wherein: the antenna board (120) is provided with a dielectric (130) and an antenna electrode (122B); and the rigid board (300) is provided with a dielectric (330) formed by stacking a plurality of dielectric layers on one another, and a wiring electrode (322B). The antenna electrode (122B) is electrically connected to the wiring electrode (322B). The dielectric (330) has an upper surface (US) and a lower surface (BS) perpendicular to a stacking direction, and sandwiches the dielectric (130) by a portion of the dielectric (130) being disposed between the upper surface (US) and the lower surface (BS). The antenna electrode (122B) has formed therein a first recessed portion in which a region overlapping the wiring electrode (322B) when viewed from the stacking direction is recessed.

Description

Connection structure and antenna module

The present disclosure relates to a connection structure and an antenna module, and more particularly to a technique for improving connection strength between substrates in an antenna module including two substrates.

International Publication No. 2009/113202 (Patent Document 1) discloses a connection structure for connecting a multilayer substrate and a flexible substrate.

In the connection structure disclosed in Patent Document 1, the ends of the flexible substrate are connected so as to be embedded inside the multilayer substrate. A flexible substrate bends in a connected state. In the connection structure of Patent Document 1, the end of the flexible substrate is embedded inside the multilayer substrate. not communicated to department. Patent Document 1 describes that the connection reliability between the multilayer substrate and the flexible substrate is thereby improved.

WO2009/113202

However, in the connection structure of Patent Document 1, when a force is applied to one of the connected substrates in the direction in which the substrate is pulled out from the connection portion, that is, in the extension direction of the substrate, the degree of adhesion between the two substrates decreases. If it is weak, the connection between the two boards may break.

The present disclosure has been made to solve such problems, and an object of the present disclosure is to provide a connection structure for connecting two substrates, in which a connection portion is provided for one of the substrates connected. To improve the connection strength between substrates when a force is applied in the direction in which they are pulled out from a substrate.

A connection structure according to one aspect of the present disclosure is a connection structure for connecting a first substrate and a second substrate, the first substrate comprising a first dielectric and a first electrode, the second substrate comprising: , a second dielectric formed by stacking a plurality of dielectric layers, and a second electrode. The first electrode is electrically connected to the second electrode. The second dielectric has a first surface and a second surface perpendicular to the stacking direction of the second dielectric. The second dielectric sandwiches dielectric 130 by placing a portion of dielectric 130 between upper surface US and lower surface BS. A first recess is formed in the first electrode, in which a region overlapping with the second electrode is recessed when viewed from above in the stacking direction.

In the connection structure according to the present disclosure, when viewed from above in the stacking direction of the second dielectric, the first electrode provided on the first substrate has a first concave portion that is recessed in a region overlapping with the second electrode provided on the second substrate. is formed. By adopting such a structure, the contact area between the two substrates is increased and the degree of adhesion is increased compared to a connection structure in which the above-described region of the first electrode is not recessed, so that the connection strength between the substrates is improved. becomes possible.

1 is an example of a block diagram of a communication device according to Embodiment 1. FIG. 2A and 2B are a plan view and a cross-sectional view of a connection portion between an antenna substrate and a rigid substrate in Embodiment 1. FIG. 4 is an enlarged view of the antenna electrode of the antenna substrate according to Embodiment 1 when viewed in plan from the positive direction of the Z-axis; FIG. 2 is a cross-sectional view of the antenna substrate and the rigid substrate in Embodiment 1. FIG. 8A and 8B are a plan view and a cross-sectional view of a connection portion between an antenna substrate and a rigid substrate in Embodiment 2; FIG. FIG. 10 is a cross-sectional view of an antenna substrate and a rigid substrate in Embodiment 2; FIG. 10 is a diagram showing a first modification of the connection structure between the antenna substrate and the rigid substrate according to the second embodiment; FIG. 10 is a diagram showing a second modification of the connection structure between the antenna substrate and the rigid substrate in the second embodiment; 8A and 8B are a plan view and a cross-sectional view of a connection portion between an antenna substrate and a rigid substrate in Embodiment 3; FIG. 11 is a cross-sectional view of an antenna substrate and a rigid substrate in Embodiment 3; FIG. 10 is a diagram showing a first modification of the connection structure between the antenna substrate and the rigid substrate in Embodiment 3; FIG. 12 is a diagram showing a second modification of the connection structure between the antenna substrate and the rigid substrate in the third embodiment; FIG. 12 is a diagram showing a third modification of the connection structure between the antenna substrate and the rigid substrate in the third embodiment; FIG. 11 is a diagram for explaining details of a connection structure between an antenna substrate and a rigid substrate in Embodiment 4; FIG. 11 is a diagram for explaining details of a connection structure between an antenna substrate and a rigid substrate according to Embodiment 5;

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. The same or corresponding parts in the drawings are denoted by the same reference numerals, and the description thereof will not be repeated.

[Embodiment 1]
(Basic configuration of communication device)
FIG. 1 is an example of a block diagram of a communication device 10 according to Embodiment 1. As shown in FIG. The communication device 10 is, for example, a mobile terminal such as a mobile phone, a smart phone or a tablet, a personal computer having a communication function, or a base station. An example of the frequency band of the radio waves used in the antenna module 100 in Embodiment 1 is, for example, millimeter wave band radio waves with center frequencies of 28 GHz, 39 GHz, and 60 GHz. It is possible.

Referring to FIG. 1, communication device 10 includes antenna module 100 and BBIC 200 that configures a baseband signal processing circuit. The antenna module 100 includes an RFIC 110 that is an example of a feeding circuit, and an antenna substrate 120 . The communication device 10 up-converts a signal transmitted from the BBIC 200 to the antenna module 100 into a high-frequency signal in the RFIC 110 and radiates it from the antenna substrate 120 via the rigid substrate 300 . Further, the communication device 10 transmits a high-frequency signal received by the antenna substrate 120 to the RFIC 110 via the rigid substrate 300, down-converts the signal, and then processes the signal by the BBIC 200. FIG.

In FIG. 1, for ease of explanation, only configurations corresponding to four radiation electrodes 121 among the plurality of radiation electrodes 121 constituting the antenna substrate 120 are shown, and other radiation electrodes 121 having similar configurations are shown. Corresponding structures are omitted. Note that FIG. 1 shows an example in which the antenna substrate 120 is formed of a plurality of radiation electrodes 121 arranged in a two-dimensional array. A case where the antenna substrate 120 is formed of the electrode 121 may be used. A one-dimensional array in which a plurality of radiation electrodes 121 are arranged in a line may also be used. In Embodiment 1, radiation electrode 121 is described as an example of a patch antenna having a substantially square flat plate shape. may be

RFIC 110 includes switches 111A to 111D, 113A to 113D, 117, power amplifiers 112AT to 112DT, low noise amplifiers 112AR to 112DR, attenuators 114A to 114D, phase shifters 115A to 115D, and signal combiner/demultiplexer. 116 , a mixer 118 and an amplifier circuit 119 .

When transmitting high-frequency signals, the switches 111A to 111D and 113A to 113D are switched to the power amplifiers 112AT to 112DT, and the switch 117 is connected to the amplifier circuit 119 on the transmission side. When receiving a high frequency signal, switches 111A to 111D and 113A to 113D are switched to low noise amplifiers 112AR to 112DR, and switch 117 is connected to the receiving amplifier of amplifier circuit 119. FIG.

A signal transmitted from the BBIC 200 is amplified by the amplifier circuit 119 and up-converted by the mixer 118 . A transmission signal, which is an up-converted high-frequency signal, is divided into four waves by the signal combiner/demultiplexer 116, passes through four signal paths, and is fed to different radiation electrodes 121, respectively. At this time, the directivity of the antenna substrate 120 can be adjusted by individually adjusting the degree of phase shift of the phase shifters 115A to 115D arranged in each signal path. Attenuators 114A-114D also adjust the strength of the transmitted signal.

The received signals, which are high-frequency signals received by each radiation electrode 121 , pass through four different signal paths and are multiplexed by the signal combiner/demultiplexer 116 . The multiplexed received signal is down-converted by mixer 118 , amplified by amplifier circuit 119 , and transmitted to BBIC 200 .

The RFIC 110 is formed, for example, as a one-chip integrated circuit component including the above circuit configuration. Alternatively, devices (switches, power amplifiers, low-noise amplifiers, attenuators, phase shifters) corresponding to each radiation electrode 121 in the RFIC 110 may be formed as one-chip integrated circuit components for each corresponding radiation electrode 121. .

(Connection structure between antenna board and wiring board)
Next, details of the connection structure between the antenna substrate 120 and the rigid substrate 300 in FIG. 1 will be described with reference to FIGS. 2, 3, and 4. FIG. 2A and 2B are a plan view (FIG. 2(a)) and a cross-sectional view (FIG. 2(b)) of the connecting portion of the antenna substrate 120 and the rigid substrate 300 along the line II-II in FIG.

FIG. 3 is an enlarged view of the

antenna electrodes

122A and 122B of the antenna substrate 120 when viewed from the positive direction of the Z axis. FIG. 4 is a cross-sectional view taken along line III-III of FIG. 2(a). 2, 3, and 4, the case where the antenna substrate 120 forms a dipole antenna will be described.

In the following description, the thickness direction of the antenna substrate 120 is defined as the Z-axis direction, and the plane perpendicular to the Z-axis direction is defined as the X-axis and the Y-axis. In addition, the positive direction of the Z-axis in each drawing may be referred to as the upper surface side, and the negative direction thereof as the lower surface side. The antenna substrate 120 corresponds to the "first substrate" in the present disclosure, and the rigid substrate 300 corresponds to the "second substrate" in the present disclosure.

With reference to FIGS. 2(a) and 2(b), the antenna substrate 120 and the rigid substrate 300 are connected. Antenna substrate 120 includes dielectric 130 and

antenna electrodes

122A and 122B. Rigid substrate 300 includes dielectric 330,

wiring electrodes

322A and 322B, and ground electrode GND. The dielectric 330 is formed by laminating a plurality of dielectric layers in the Z-axis direction. The dielectric layer forming dielectric 330 is, for example, a liquid crystal polymer (LCP). Note that the dielectric 330 corresponds to the "second dielectric" in the present disclosure.

In the connection structure shown in Embodiment 1, the antenna substrate 120 and the rigid substrate 300 are compressed, heated, and baked to bring the substrates into close contact with each other. Thereby, the antenna substrate 120 and the rigid substrate 300 are connected to each other.

The thickness (dimension in the Z-axis direction) of the dielectric 130 of the antenna substrate 120 is thinner than the thickness of the dielectric 330 of the rigid substrate 300 . Referring to FIG. 2B, dielectric 330 has an upper surface US and a lower surface BS perpendicular to the dielectric stacking direction. A portion of the antenna substrate 120 is positioned between the top surface US of the dielectric 330 and the bottom surface BS of the dielectric 330 . That is, in the connection structure of FIG. 2, the end portion of the antenna substrate 120 on the negative direction side of the X-axis is embedded in the rigid substrate 300 for connection.

The upper surface US of the dielectric 330 corresponds to the "first surface" in the present disclosure, and the lower surface BS of the dielectric 330 corresponds to the "second surface".

In the antenna substrate 120, the

antenna electrodes

122A and 122B are arranged on the surface of the dielectric 130 on the positive direction side of the Z axis. The ends of the

antenna electrodes

122A and 122B on the positive direction side of the X-axis function as the radiation electrode 121 . That is, the

antenna electrodes

122A and 122B form a dipole antenna that radiates radio waves from the radiation electrode 121 by being differentially fed from the RFIC 110 .

Also, each of the

antenna electrodes

122A and 122B has a mesh shape when viewed from above in the positive direction of the Z axis. The mesh shape of the

antenna electrodes

122A and 122B will be described with reference to FIG. As shown in FIG. 3, the

antenna electrodes

122A and 122B are formed by weaving together a plurality of linear conductors. The distance D1 between the linear conductors is 50-100 μm. The width of one linear conductor, that is, the thickness of the linear conductor is 1 to 2 μm. In this way, since the

antenna electrodes

122A and 122B are formed by weaving thin linear conductors, the

antenna electrodes

122A and 122B block most of the light emitted from the negative direction side of the Z axis. It can be passed in the positive direction of the Z-axis without any need. Note that the antenna electrode 122A or the antenna electrode 122B corresponds to the "first electrode" in the present disclosure.

Returning to FIG. 2, the dielectric 130 is, for example, a film made of translucent PET (Polyethylene Terephthalate) material. Accordingly, in the antenna substrate 120 according to the first embodiment, most of the light emitted from the negative side of the Z-axis can pass through in the positive direction of the Z-axis with respect to the dielectric 130 .

That is, when the communication device 10 is a mobile terminal such as a smartphone and the antenna substrate 120 is arranged so as to overlap the display, the user's view of the display through the antenna substrate 120 is not hindered. In other words, the

antenna electrodes

122A and 122B are less visible to the user with the naked eye. The dielectric 130 of the antenna substrate 120 may be a multi-layer substrate. Note that the dielectric 130 corresponds to the "first dielectric" in the present disclosure.

Dielectric 130 or dielectric 330 is, for example, a low temperature co-fired ceramics (LTCC) multi-layer substrate, or a multi-layer resin formed by laminating a plurality of resin layers composed of resin such as epoxy or polyimide. A substrate, a multilayer resin substrate formed by laminating multiple resin layers composed of liquid crystal polymer (LCP) with a lower dielectric constant, and a multilayer resin substrate formed by laminating multiple resin layers composed of fluorine resin It may be a multi-layered resin substrate or a ceramics multi-layer substrate other than LTCC. Alternatively, dielectric 130 or dielectric 330 may be made of glass or plastic.

In FIG. 2(b), a cross section taken along line II-II is illustrated in order to describe the connection between the wiring electrode 322B and the antenna electrode 122B. Inside the rigid substrate 300,

wiring electrodes

322A and 322B and a ground electrode GND are arranged. 2B, the ground electrode GND, the antenna substrate 120, the

wiring electrodes

322A, 322A, 322A, 322A, 322A, 322A, 322A, 322A, 322A, 322A, 322A, 322A, 322A, 322A, 322B, 322A, 322B, 322A, 322B, 322A, 322B, 322A, 322B, 322A, 322B, 322A, 322B, 322A, 322B, 322A, 322B, 322A, 322B, 322B is arranged.

Regarding the connection structure between the wiring electrode 322A and the antenna electrode 122A, although not shown, it has the same connection structure as the connection structure between the wiring electrode 322B and the antenna electrode 122B shown in FIG. 2(b). Although not shown in FIG. 2A, the ground electrode GND is a flat plate electrode having an XY plane surface that overlaps with both of the

wiring electrodes

322A and 322B when viewed from the Z-axis direction.

As shown in FIG. 2(b), the wiring electrode 322B and the antenna electrode 122B are connected by vias VB. That is, the

wiring electrodes

322A, 322B are electrically connected to the

antenna electrodes

122A, 122B through vias.

The ground electrode GND is a ground electrode that serves as a reference potential. The impedance of the

wiring electrodes

322A, 322B and the

antenna electrodes

122A, 122B is 50Ω with respect to the reference potential of the ground electrode GND.

As shown in FIG. 2(b), the antenna electrode 122B extends downward in the negative direction of the Z-axis from the outside to the inside of the rigid substrate 300. As shown in FIG. That is, the concave portion H is formed in the antenna electrode 122B. The concave portion H is formed in a region overlapping with the wiring electrode 322B when viewed from above in the stacking direction of the dielectric 330 . The recess H of the antenna electrode 122B corresponds to the "first recess" of the present disclosure.

FIG. 4 illustrates a cross section of the rigid substrate 300 taken along line III-III in FIG. 2(a) after the antenna electrode 122B has fallen in the negative direction of the Z axis. 2A, the dielectric 330 of the rigid substrate 300 includes, in order from the negative direction of the Z axis, the ground electrode GND, the dielectric 130, the antenna electrode 122B, the via VB, and the wiring electrode 322B. include.

Since the recess H is formed in the antenna electrode 122B, the antenna electrode 122B extends downward in the negative direction of the Z axis. Therefore, the recess H1 is formed in the dielectric 130 so as to be recessed in the negative direction of the Z-axis corresponding to the depression of the antenna electrode 122B. Antenna electrode 122B is arranged so as to be in contact with the surface of dielectric 130 that forms recess H1. In Embodiment 1, recess H1 is formed to be recessed by half the thickness of dielectric 130 (dimension in the Z-axis direction).

In the connection structure in which one substrate is partially embedded in the other substrate as shown in the first embodiment, the connection structure is such that one substrate is pulled out in the extending direction of the substrate. If the adhesion between the substrates is weak when a force is applied, the connection between the substrates may be broken.

In the connection structure according to Embodiment 1, as shown in FIG. 2B, the concave portion H is formed in the antenna electrode 122B. The area of contact between 122B and dielectric 330 increases. As a result, in the connection structure according to the first embodiment, it is possible to further improve the adhesion between the antenna electrode 122B and the dielectric 330 when compressing and heating in the manufacturing stage.

Further, by forming the concave portion H in the antenna electrode 122B, the concave portion H1 is formed in the dielectric 130, and the contact area between the dielectric 130 and the dielectric 330 increases. Thus, in the connection structure according to the first embodiment, the degree of adhesion between

dielectrics

130 and 330 can be further improved when compression and heating are performed in the manufacturing stage.

In addition, the dielectric 130 is formed with a concave portion H1 in which a region overlapping the wiring electrode 322B and the antenna electrode 122B is concave when viewed from the stacking direction of the dielectric 330 . That is, in the connection structure according to the first embodiment, since the concave portion H1 is formed, the antenna electrode B is compressed so as to be pushed into the dielectric 130 in the manufacturing stage, and the antenna electrode 122B and the dielectric 130 are compressed. It also increases the contact area between Thus, in the connection structure according to the first embodiment, not only the degree of adhesion between dielectric 130 and dielectric 330 but also the degree of adhesion between dielectric 130 and antenna electrode 122B can be improved.

As described above, according to the connection structure in Embodiment 1, the degree of adhesion between antenna electrode 122B and dielectric 330 can be improved. The degree of adhesion between the substrates can be improved, and the connection strength between the substrates is improved. That is, compared to the connection structure in which the recess H and the recess H1 are not formed in the dielectric 130, in the connection structure according to the first embodiment, a force is applied to pull out the antenna substrate 120 in the positive direction of the X axis. Even in this case, the connection between the antenna substrate 120 and the rigid substrate 300 is less likely to break.

[Embodiment 2]
In the connection structure of the first embodiment, the configuration in which the recesses are formed in the antenna electrode 122B of the antenna substrate 120 and the dielectric 130 has been described. In the second embodiment, an example in which a convex portion is formed on the lower surface of dielectric 130A and a concave portion is formed on ground electrode GNDA will be described.

5 and 6, the details of the connection structure between the antenna substrate 120 and the rigid substrate 300 in Embodiment 2 will be described. 5A and 5B are a plan view (FIG. 5A) and a cross-sectional view (FIG. 5B) taken along line II-II of FIG. FIG. 6 is a cross-sectional view taken along line III--III of FIG. 5(a).

5 and 6, the shapes of the dielectric 130 and the ground electrode GND in FIGS. 2 and 4 described in the first embodiment are changed, and other configurations are the same. 5 and 6, the description of elements similar to those in FIGS. 2 and 4 of Embodiment 1 will not be repeated.

Referring to FIG. 6, the dielectric 130A has a convex portion formed on the lower surface of the dielectric 130A at a position corresponding to the concave portion formed on the upper surface. Referring to FIG. 5B, dielectric 130A, like antenna electrode 122B, extends from the outside to the inside of rigid substrate 300 after falling in the negative direction of the Z axis. Since dielectric 130A has a convex portion on the lower surface, concave portion H1A is formed to be concave by the same thickness as dielectric 130 (dimension in the Z-axis direction).

That is, compared to the connection structure of the first embodiment, the contact area between dielectric 130A and dielectric 330 is further increased, and the thickness of dielectric 130A can be reduced. That is, the degree of adhesion between dielectric 130A and dielectric 330 is further improved during compression and heating in the manufacturing stage. The recess H1A may be recessed larger than the thickness of the dielectric 130A. For example, the recess H1A is formed so as to be recessed to a thickness that is twice the thickness of the dielectric 130A.

The recess H2 formed in the ground electrode GNDA will be described below. In the ground electrode GNDA included in the rigid substrate 300 of the second embodiment, a concave portion H2 is formed in a region where the antenna electrode 122B and the wiring electrode 322B overlap when viewed from above in the stacking direction of the dielectric 330 . That is, the recess H2 is arranged in a region of the ground electrode GNDA that overlaps with the recess H1A when viewed in plan from the Z-axis direction.

The recess H2 is formed so as to be recessed in the negative direction of the Z-axis, similar to the recess H1A. That is, the recess H2 is recessed in the same direction as the recess H1A. The "recess H2" in Embodiment 2 corresponds to the "second recess" in the present disclosure.

The ground electrode GNDA includes a ground electrode GNDL, a ground electrode GNDC, and a ground electrode GNDR. The ground electrode GNDC overlaps the antenna electrode 122B and the wiring electrode 322B when viewed from above in the stacking direction. As for the ground electrode GNDL and the ground electrode GNDR, the antenna electrode 122B and the wiring electrode 322B do not overlap when viewed in plan from the stacking direction.

Referring to FIG. 6, ground electrode GNDC is formed in a dielectric layer having bottom surface BS among the dielectric layers forming dielectric 330 . That is, the ground electrode GNDC is formed inside the dielectric layer arranged on the most negative direction side of the Z axis. On the other hand, the ground electrode GNDL and the ground electrode GNDR are arranged in a dielectric layer arranged on the positive direction side of the Z-axis of the dielectric layer where the ground electrode GNDC is arranged. That is, the ground electrode GNDC and the ground electrodes GNDL and GNDR are arranged on different dielectric layers.

The ground electrode GNDC is connected to the ground electrode GNDL and the ground electrode GNDR through vias. The method for connecting the ground electrode GNDC to the ground electrodes GNDL and GNDR is not limited to the method using vias. For example, an electrically conductive adhesive or the like may be used.

"Ground electrode GNDC" corresponds to the "first ground electrode" in the present disclosure. “Ground electrode GNDL” and “ground electrode GNDR” correspond to “second ground electrode” in the present disclosure.

Thereby, the ground electrode GNDA can match the impedance between the wiring electrode 322B and the antenna electrode 122B more reliably than the ground electrode GND of the first embodiment. Antenna electrode 122B and wiring electrode 322B are electrically coupled to ground electrode GNDA to transmit a high frequency signal. That is, the antenna electrode 122B and the ground electrode GNDA function as a stripline.

A plurality of electric lines of force are generated between the antenna electrode 122B and the wiring electrode 322B functioning as a strip line and the ground electrode GNDA. When transmitting a high-frequency signal in a stripline, it is desirable that the dielectric constant of the region through which the lines of electric force pass is uniform.

By forming the concave portion H2 in the ground electrode GNDA, the ratio of the dielectric 130 and the dielectric 330 through which all the lines of electric force pass becomes more uniform. In other words, the difference in dielectric constant between regions through which all electric lines of force each pass becomes small.

In the connection structure of the second embodiment, the recess H2 is formed in the ground electrode GNDA in a region overlapping the recess H1A when viewed from the Z-axis direction. As a result, the difference in dielectric constant between the antenna electrode 122B/wiring electrode 322B and the ground electrode GNDA through which the lines of electric force pass can be suppressed. Therefore, the ground electrode GNDA can more reliably match the impedance between the wiring electrode 322B and the antenna electrode 122B.

(Modification 1 of Embodiment 2)
FIG. 7 shows a first modification of the connection structure between the antenna substrate 120 and the rigid substrate 300 according to the second embodiment. In Modification 1 of Embodiment 2, electronic components IC<b>1 and IC<b>2 are mounted on lower surface BS of dielectric 330 .

The electronic components IC1 and IC2 are, for example, RFIC110 or BBIC200. Note that the electronic components IC1 and IC2 may be other electronic components. Electronic components IC<b>1 and IC<b>2 may be mounted on top surface US of dielectric 330 . As described above, in Modification 1 of Embodiment 2, an arbitrary electronic component can be mounted even in the vicinity of the connecting portion between antenna substrate 120 and rigid substrate 300 .

The electronic components IC1 and IC2 are mounted on the lower surface BS in a region that does not overlap the concave portion H2 when viewed from the Z-axis direction. The lower surface BS of the dielectric 330 may not have sufficient flatness due to the influence of the recess H2 in the region overlapping the recess H2 of the ground electrode GNDA. If the electronic components IC1 and IC2 are mounted on the lower surface BS that is not sufficiently flat, there is a risk that the electronic components IC1 and IC2 will be poorly connected.

In the connection structure shown in FIG. 7, the electronic components IC1 and IC2 are mounted on the lower surface BS in a region that does not overlap the concave portion H2 when viewed from the Z-axis direction. IC1 and IC2 can be mounted, and connection failure can be prevented.

(Modification 2 of Embodiment 2)
FIG. 8 is a diagram showing a second modification of the connection structure between the antenna substrate 120 and the rigid substrate 300 according to the second embodiment. In Modified Example 2 of Embodiment 2, the electronic component IC1 is located in a region A1 that does not overlap with the concave portion H2 and overlaps with the portion of the ground electrode GNDA where the concave portion H2 is not formed when viewed from above in the Z-axis direction. Implemented.

As shown in FIG. 8, the area A1 becomes an area isolated from other areas of the dielectric 330 by forming the recess H2 in the ground electrode GNDA. In FIG. 8, the area A1 can be effectively utilized by mounting the electronic component IC1 in the isolated area A1. In particular, as shown in FIG. 8, when the end of the ground electrode GNDA on the negative direction side of the Y axis is close to the end of the dielectric 330 on the negative direction side of the Y axis, the electronic component is placed in the area A1. By mounting, the area A1 can be used more effectively.

[Embodiment 3]
In the first and second embodiments described above, the configuration in which the antenna electrode 122B and the wiring electrode 322B are connected through the via VB has been described. In Embodiment 3, an example in which the antenna electrode 122B and the wiring electrode 322B are in direct contact will be described.

9 and 10, the details of the connection structure between the antenna substrate 120 and the rigid substrate 300 in Embodiment 3 will be described. 9A and 9B are a plan view (FIG. 9(a)) and a cross-sectional view (FIG. 9(b)) of the connecting portion of the antenna substrate 120 and the rigid substrate 300, taken along the line II-II in FIG. 9(a). FIG. 10 is a cross-sectional view taken along line III-III of FIG. 9(a).

In the third embodiment, the antenna electrode 122B and the wiring electrode 322B are electrically connected without using the via VB in FIGS. Other configurations are the same. In the third embodiment, description of elements similar to those in FIGS. 5 and 6 of the second embodiment will not be repeated.

The wiring electrode 322B and the antenna electrode 122B are in direct contact without vias. As shown in FIGS. 9B and 10, the wiring electrode 322B and the antenna electrode 122B are in surface contact. Thus, in the connection structure of the third embodiment, since vias are not used, the cost for connecting the wiring electrode 322B and the antenna electrode 122B can be reduced. Further, in the connection structure of Embodiment 3, the connection strength between the wiring electrode 322B and the antenna electrode 122B can be further improved by increasing the surface contact area between the wiring electrode 322B and the antenna electrode 122B. Furthermore, the connection resistance between the wiring electrode 322B and the antenna electrode 122B can be reduced.

(Modification 1 of Embodiment 3)
FIG. 11 shows a first modification of the connection structure between the antenna substrate 120 and the rigid substrate 300 according to the third embodiment. In Modification 1 of Embodiment 3, antenna substrate 120 and rigid substrate 300 are connected by conductive adhesive G1.

Referring to FIG. 11, the conductive adhesive G1 is arranged between the antenna electrode 122B and the wiring electrode 322B, and electrically or physically connects the antenna electrode 122B and the wiring electrode 322B. The conductive adhesive G1 is, for example, an epoxy-based or silicone-based resin containing a conductive filler. Also, the conductive adhesive may be other thermosetting resins and solders.

Accordingly, in Modification 1 of Embodiment 3, the physical connection strength between the antenna electrode 122B and the wiring electrode 322B is improved. Furthermore, by improving the physical connection strength, it is possible to prevent poor contact between the antenna electrode 122B and the wiring electrode 322B, and as a result, it is possible to improve the electrical connection strength.

(Modification 2 of Embodiment 3)
FIG. 12 shows a second modification of the connection structure between the antenna substrate 120 and the rigid substrate 300 according to the third embodiment. In Modification 2 of Embodiment 3, antenna substrate 120 and rigid substrate 300 are connected via a plurality of vias.

Referring to FIG. 12, via V1, via V2, via V3 and via V4 are arranged between antenna electrode 122B and wiring electrode 322B to electrically and physically connect antenna electrode 122B and wiring electrode 322B. do.

As a result, compared with the case where the number of vias connecting the antenna electrode 122B and the wiring electrode 322B is one, in the modification 2 of the third embodiment, the physical distance between the antenna electrode 122B and the wiring electrode 322B is reduced. Improves connection strength.

Furthermore, by arranging a plurality of vias V1 to V4 between the antenna electrode 122B and the wiring electrode 322B, there are a plurality of paths through which high-frequency signals flow between the antenna electrode 122B and the wiring electrode 322B. The connection strength can be further improved, and the connection resistance between the antenna electrode 122B and the wiring electrode 322B can be reduced. Also, in FIG. 12, a configuration in which a plurality of vias V1 to V4 are arranged in the X-axis direction has been described, but a configuration in which a plurality of vias are arranged in the Y-axis direction is also possible.

(Modification 3 of Embodiment 3)
FIG. 13 shows a third modification of the connection structure between the antenna substrate 120 and the rigid substrate 300 according to the third embodiment. 13 shows a plan view of the antenna substrate 120 (FIG. 13(a)) and a sectional view of the connection structure between the antenna substrate 120 and the rigid substrate 300 (FIG. 13(b)).

In the connection structure shown in FIG. 13, the antenna electrode 122B is arranged at a distance D2 from the end of the dielectric 130A on the negative direction side of the X axis. That is, with reference to FIG. 13(a),

antenna electrodes

122A and 122B are arranged inside the outer peripheral edge of dielectric 130A when viewed from the positive direction of the Z axis.

Referring to FIG. 13B, when force is applied only to dielectric 130A in the pull-out direction, since

antenna electrodes

122A and 122B are joined to vias, dielectric 130A and

antenna electrodes

122A and 122A The connection with 122B may be broken and only the dielectric 130A may be pulled out.

Therefore, in the connection structure shown in FIG. 13, the antenna electrode 122B is arranged at a distance D2 from the end of the dielectric 130A on the negative direction side of the X axis, so that force is applied only to the dielectric 130A. Even if it does, a region of dielectric 130A corresponding to distance D2 will catch on antenna electrode 122B. Therefore, only the dielectric 130A can be prevented from being cut, and the connection strength between the antenna substrate 120 and the rigid substrate 300 is improved.

[Embodiment 4]
In Embodiments 1 to 3 above, the configuration in which the antenna substrate 120 forms a dipole antenna has been described. In Embodiment 4, an example of forming a patch antenna will be described.

FIG. 14 is a diagram for explaining the details of the connection structure between the

antenna boards

120C and 120D and the rigid board 300 according to the fourth embodiment. 14 shows a plan view (FIG. 14(a)) of the connecting portion of the antenna substrate 120C and the rigid substrate 300 and a cross-sectional view (FIG. 14(b)) taken along the line II-II in FIG. 14(a). In the fourth embodiment, description of elements similar to those of the first to third embodiments will not be repeated.

Referring to FIG. 14, rigid board 300 is connected to two boards, antenna board 120C and antenna board 120D. Antenna substrate 120C includes dielectric 130C and antenna electrode 122C. A square region of the antenna electrode 122C shown in FIG. 14(a) functions as the radiation electrode 121C of the patch antenna.

The antenna substrate 120D includes a dielectric 130D and a ground electrode GNDB. That is, the ground electrode GNDB functions as a ground electrode electrically coupled with the radiation electrode 121C of the patch antenna. That is, in FIG. 14, the patch antenna is formed by the square area of the antenna substrate 120D and the area of the ground electrode GNDB that overlaps with the square area when viewed from the Z-axis direction.

The rigid substrate 300 includes

wiring electrodes

332C and 332D. The

wiring electrodes

332C and 332D are electrically connected to the antenna electrode 122C and the ground electrode GNDB, respectively.

Thus, the connection structure shown in Embodiments 1 to 3 can also be used between the

antenna substrates

120C and 120D forming patch antennas and the rigid substrate 300. FIG.

[Embodiment 5]
In Embodiments 1 to 4 above, the configuration in which the antenna substrate 120 forms one antenna has been described. In Embodiment 5, an example in which the connection structure of the present application is applied to an array antenna forming a plurality of antennas will be described.

FIG. 15 is a diagram for explaining the details of the connection structure between the antenna substrate 120E and the rigid substrate 300 according to the fifth embodiment. FIG. 15 shows a plan view of the connecting portion of the antenna substrate 120E and the rigid substrate 300. As shown in FIG. In the fifth embodiment, description of elements similar to those of the first to fourth embodiments will not be repeated.

Referring to FIG. 15, antenna substrate 120E includes dielectric 130B and antenna electrodes 122AD, 122BD, 122AE, 122BE, 122AF, 122BF, 122AG and 122BG. The rigid substrate 300 includes a dielectric 330 and wiring electrodes 332AD, 332BD, 332AE, 332BE, 332AF, 332BF, 332AG and 332BG. The antenna electrodes 122AD-122BG are electrically connected to the wiring electrodes 332AD-332BG, respectively.

The end of each of the antenna electrodes 122AD and 122BD on the positive direction side of the X axis functions as a radiation electrode 121D. That is, the antenna electrodes 122AD and 122BD are differentially fed from the RFIC 110 to form a dipole antenna that radiates radio waves from the radiation electrode 121D. Similarly, antenna electrodes 122AE, 122BE-122AG, and 122BG form dipole antennas that radiate radio waves from radiation electrodes 121D-121G, respectively.

Thus, even when the antenna substrate 120E is an array antenna forming a plurality of antennas, it is possible to use the connection structure shown in Embodiments 1 to 4. By forming an array antenna, the antenna characteristics of the antenna substrate 120E can be improved. The array antenna included in the antenna substrate 120E may be composed of a plurality of patch antennas shown in FIG.

Each of the antenna electrodes 122AE-122AG and the antenna electrodes 122BE-122BG corresponds to the "third electrode" in the present disclosure. Each of the wiring electrodes 322AD-322AG and the wiring electrodes 322BD-322BG corresponds to the "fourth electrode" in the present disclosure. Each of the radiation electrodes 121E-121G corresponds to the "third radiation electrode" in the present disclosure.

Although FIG. 15 describes the configuration in which the antenna substrate 120E includes the antenna electrodes 122AD to 122AG and 122BD to 122BG, the antenna substrate 120E may include only one antenna electrode to form an array antenna. That is, the antenna substrate 120E has only one antenna electrode connected to one wiring electrode included in the rigid substrate 300. FIG. One antenna electrode is branched within the antenna substrate 120E to form radiation electrodes 121D to 121G.

As a result, the number of wiring electrodes and antenna electrodes used can be reduced, and costs can be reduced.

The embodiments disclosed this time should be considered illustrative in all respects and not restrictive. The scope of the present invention is indicated by the scope of the claims rather than the description of the above-described embodiments, and is intended to include all modifications within the meaning and scope equivalent to the scope of the claims.

10 communication device, 100 antenna module, 111A to 111D, 113A to 113D, 117 switch, 112AR to 112DR low noise amplifier, 112AT to 112DT power amplifier, 114A to 114D attenuator, 115A to 115D phase shifter, 116 branching filter, 118 Mixer, 119 Amplifier circuit, 120, 120C to 120E Antenna substrate, 121, 121C to 121G Radiation electrode, 122A, 122B, 122C, 122AD to 122BG Antenna electrode, 130, 130A to 130D, 330 Dielectric, 300 Rigid substrate, 322A, 332C, 332D, 322AD to 332BG wiring electrodes, A1 area, BS lower surface, US upper surface, D1, D2 distance, G1 conductive adhesive, GND, GNDA, GNDB ground electrode, H, H1, H1A, H2 concave portions, IC1, IC2 Electronic parts, II, III lines, V1, V2, V3, V4, VB vias.

Claims

A connection structure for connecting a first substrate and a second substrate,
the first substrate comprises a first dielectric and a first electrode;
the second substrate includes a second dielectric formed by stacking a plurality of dielectric layers and a second electrode;
the first electrode is electrically connected to the second electrode;
the second dielectric has a first surface and a second surface perpendicular to the stacking direction of the second dielectric;
the second dielectric sandwiches the first dielectric by a portion of the first dielectric being disposed between the first surface and the second surface;
The connection structure, wherein the first electrode is formed with a first concave portion in which a region overlapping with the second electrode when viewed in plan from the stacking direction is concave.
The second substrate further comprises a ground electrode,
The ground electrode has a second concave portion in which a region where the first electrode and the second electrode overlap when viewed from above in the stacking direction is concave,
2. The connection structure according to claim 1, wherein said second recess is recessed in the same direction as said first recess.
The ground electrode is
a first ground electrode in which the first electrode and the second electrode overlap when viewed in plan from the stacking direction;
including a second ground electrode in which the first electrode and the second electrode do not overlap when viewed in plan from the stacking direction;
3. The connection structure according to claim 2, wherein each of said first ground electrode and said second ground electrode is formed on a different dielectric layer among a plurality of dielectric layers forming said second dielectric.
The second substrate further comprises an electronic component,
4. The connection structure according to claim 2, wherein said electronic component is mounted on said second surface in a region that does not overlap said first dielectric when viewed from above in said stacking direction.
The second substrate further comprises an electronic component,
4. The connection structure according to claim 2, wherein said electronic component is mounted on said second surface in a region that does not overlap with said second concave portion when viewed from above in said stacking direction.
The connection structure according to any one of claims 1 to 5, wherein the first electrode is in direct contact with the second electrode.
6. The method according to any one of claims 1 to 5, further comprising a conductive adhesive disposed between said first electrode and said second electrode and connecting said first electrode and said second electrode. connection structure.
The connection structure according to any one of claims 1 to 5, further comprising at least one via connecting said first electrode and said second electrode.
The connection structure according to any one of claims 1 to 8, wherein the first electrode is arranged inside the outer peripheral edge of the first dielectric when viewed in plan from the stacking direction.
The connection structure according to any one of claims 1 to 9, wherein the first electrode has a mesh shape when viewed in plan from the stacking direction.
The connection structure according to any one of claims 1 to 10, wherein the first dielectric has translucency.
An antenna module comprising the connection structure according to any one of claims 1 to 11,
The antenna module, wherein a part of the first electrode forms a first radiation electrode for radiating radio waves.
The antenna module according to claim 12, wherein said first radiation electrode forms part of a dipole antenna.
The antenna module according to claim 12, wherein said first radiation electrode forms part of a patch antenna.
The antenna module according to any one of claims 12 to 14, wherein part of said first electrode forms a second radiation electrode different from said first radiation electrode.
The first substrate further comprises a third electrode,
The second substrate further comprises a fourth electrode,
the third electrode is electrically connected to the fourth electrode;
The antenna module according to any one of claims 12 to 14, wherein part of said third electrode forms a third radiation electrode for radiating radio waves.